/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package org.apache.tomcat.websocket;

import org.apache.tomcat.util.res.StringManager;

import javax.websocket.SendHandler;
import javax.websocket.SendResult;
import java.util.concurrent.*;

/**
 * Converts a Future to a SendHandler.
 */
class FutureToSendHandler implements Future<Void>, SendHandler {

	private static final StringManager sm = StringManager.getManager(Constants.PACKAGE_NAME);

	private final CountDownLatch latch = new CountDownLatch(1);
	private final WsSession wsSession;
	private final boolean closeMessage;
	private volatile SendResult result = null;

	public FutureToSendHandler(WsSession wsSession) {
		this(wsSession, false);
	}

	public FutureToSendHandler(WsSession wsSession, boolean closeMessage) {
		this.wsSession = wsSession;
		this.closeMessage = closeMessage;
	}

	public boolean isCloseMessage() {
		return closeMessage;
	}


	// --------------------------------------------------------- SendHandler

	@Override
	public void onResult(SendResult result) {

		this.result = result;
		latch.countDown();
	}


	// -------------------------------------------------------------- Future

	@Override
	public boolean cancel(boolean mayInterruptIfRunning) {
		// Cancelling the task is not supported
		return false;
	}

	@Override
	public boolean isCancelled() {
		// Cancelling the task is not supported
		return false;
	}

	@Override
	public boolean isDone() {
		return latch.getCount() == 0;
	}

	@Override
	public Void get() throws InterruptedException,
			ExecutionException {
		try {
			wsSession.registerFuture(this);
			latch.await();
		} finally {
			wsSession.unregisterFuture(this);
		}
		if (result.getException() != null) {
			throw new ExecutionException(result.getException());
		}
		return null;
	}

	@Override
	public Void get(long timeout, TimeUnit unit)
			throws InterruptedException, ExecutionException,
			TimeoutException {
		boolean retval = false;
		try {
			wsSession.registerFuture(this);
			retval = latch.await(timeout, unit);
		} finally {
			wsSession.unregisterFuture(this);

		}
		if (retval == false) {
			throw new TimeoutException(sm.getString("futureToSendHandler.timeout",
					Long.valueOf(timeout), unit.toString().toLowerCase()));
		}
		if (result.getException() != null) {
			throw new ExecutionException(result.getException());
		}
		return null;
	}
}



